Compared with traditional light sources such as incandescent light sources, LEDs have many advantages including higher efficacy, longer lifetime, smaller size and faster switching. The smaller size of LEDs means that they can be considered as a point source when designing optics. This makes it easier and more efficient to design precise light distributions to be provided by LED light sources.
The fast switching characteristic of LEDs enables dynamic lighting effects to be created, which are becoming more and more popular both in outdoor and indoor applications.
Optical structures enable various lighting patterns to be designed, which can be provided on a target surface, which may be a flat plane such as a wall or floor, or indeed a curved surface, such as undulating ground. Normally, lighting patterns are fixed and cannot be changed after fabrication of a luminaire molding. Such fixed lighting patterns can be monotonous and uninteresting.
Luminaires are also known which can change the lighting pattern produced by adopting moving elements, but these introduce extra luminaire cost and maintenance cost.
There is therefore a need for a luminaire which provides a dynamic aesthetically interesting output, preferably without the need for mechanically moving components.